330 lines
		
	
	
		
			8.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			330 lines
		
	
	
		
			8.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * max1586.c  --  Voltage and current regulation for the Maxim 1586
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|  *
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|  * Copyright (C) 2008 Robert Jarzmik
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License as published by
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|  * the Free Software Foundation; either version 2 of the License, or
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|  * (at your option) any later version.
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|  *
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|  * This program is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  * GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public License
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|  * along with this program; if not, write to the Free Software
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|  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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|  */
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| #include <linux/module.h>
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| #include <linux/err.h>
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| #include <linux/i2c.h>
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| #include <linux/platform_device.h>
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| #include <linux/regulator/driver.h>
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| #include <linux/slab.h>
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| #include <linux/regulator/max1586.h>
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| #include <linux/of_device.h>
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| #include <linux/regulator/of_regulator.h>
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| 
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| #define MAX1586_V3_MAX_VSEL 31
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| #define MAX1586_V6_MAX_VSEL 3
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| 
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| #define MAX1586_V3_MIN_UV   700000
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| #define MAX1586_V3_MAX_UV  1475000
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| 
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| #define MAX1586_V6_MIN_UV        0
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| #define MAX1586_V6_MAX_UV  3000000
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| 
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| #define I2C_V3_SELECT (0 << 5)
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| #define I2C_V6_SELECT (1 << 5)
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| 
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| struct max1586_data {
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| 	struct i2c_client *client;
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| 
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| 	/* min/max V3 voltage */
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| 	unsigned int min_uV;
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| 	unsigned int max_uV;
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| 
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| 	unsigned int v3_curr_sel;
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| 	unsigned int v6_curr_sel;
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| };
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| 
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| /*
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|  * V6 voltage
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|  * On I2C bus, sending a "x" byte to the max1586 means :
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|  *   set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
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|  * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
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|  */
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| static const unsigned int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
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| 
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| /*
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|  * V3 voltage
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|  * On I2C bus, sending a "x" byte to the max1586 means :
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|  *   set V3 to 0.700V + (x & 0x1f) * 0.025V
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|  * This voltage can be increased by external resistors
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|  * R24 and R25=100kOhm as described in the data sheet.
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|  * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
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|  */
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| static int max1586_v3_get_voltage_sel(struct regulator_dev *rdev)
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| {
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| 	struct max1586_data *max1586 = rdev_get_drvdata(rdev);
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| 
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| 	return max1586->v3_curr_sel;
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| }
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| 
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| static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev,
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| 				      unsigned selector)
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| {
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| 	struct max1586_data *max1586 = rdev_get_drvdata(rdev);
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| 	struct i2c_client *client = max1586->client;
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| 	int ret;
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| 	u8 v3_prog;
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| 
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| 	dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
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| 		regulator_list_voltage_linear(rdev, selector) / 1000);
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| 
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| 	v3_prog = I2C_V3_SELECT | (u8) selector;
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| 	ret = i2c_smbus_write_byte(client, v3_prog);
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| 	if (ret)
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| 		return ret;
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| 
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| 	max1586->v3_curr_sel = selector;
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| 
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| 	return 0;
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| }
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| 
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| static int max1586_v6_get_voltage_sel(struct regulator_dev *rdev)
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| {
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| 	struct max1586_data *max1586 = rdev_get_drvdata(rdev);
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| 
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| 	return max1586->v6_curr_sel;
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| }
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| 
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| static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,
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| 				      unsigned int selector)
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| {
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| 	struct max1586_data *max1586 = rdev_get_drvdata(rdev);
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| 	struct i2c_client *client = max1586->client;
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| 	u8 v6_prog;
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| 	int ret;
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| 
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| 	dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
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| 		rdev->desc->volt_table[selector] / 1000);
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| 
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| 	v6_prog = I2C_V6_SELECT | (u8) selector;
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| 	ret = i2c_smbus_write_byte(client, v6_prog);
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| 	if (ret)
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| 		return ret;
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| 
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| 	max1586->v6_curr_sel = selector;
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| 
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| 	return 0;
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| }
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| 
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| /*
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|  * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
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|  * the set up value.
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|  */
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| static const struct regulator_ops max1586_v3_ops = {
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| 	.get_voltage_sel = max1586_v3_get_voltage_sel,
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| 	.set_voltage_sel = max1586_v3_set_voltage_sel,
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| 	.list_voltage = regulator_list_voltage_linear,
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| 	.map_voltage = regulator_map_voltage_linear,
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| };
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| 
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| static const struct regulator_ops max1586_v6_ops = {
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| 	.get_voltage_sel = max1586_v6_get_voltage_sel,
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| 	.set_voltage_sel = max1586_v6_set_voltage_sel,
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| 	.list_voltage = regulator_list_voltage_table,
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| };
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| 
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| static struct regulator_desc max1586_reg[] = {
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| 	{
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| 		.name = "Output_V3",
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| 		.id = MAX1586_V3,
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| 		.ops = &max1586_v3_ops,
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| 		.type = REGULATOR_VOLTAGE,
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| 		.n_voltages = MAX1586_V3_MAX_VSEL + 1,
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| 		.owner = THIS_MODULE,
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| 	},
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| 	{
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| 		.name = "Output_V6",
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| 		.id = MAX1586_V6,
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| 		.ops = &max1586_v6_ops,
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| 		.type = REGULATOR_VOLTAGE,
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| 		.n_voltages = MAX1586_V6_MAX_VSEL + 1,
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| 		.volt_table = v6_voltages_uv,
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| 		.owner = THIS_MODULE,
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| 	},
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| };
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| 
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| static int of_get_max1586_platform_data(struct device *dev,
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| 				 struct max1586_platform_data *pdata)
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| {
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| 	struct max1586_subdev_data *sub;
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| 	struct of_regulator_match rmatch[ARRAY_SIZE(max1586_reg)] = { };
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| 	struct device_node *np = dev->of_node;
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| 	int i, matched;
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| 
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| 	if (of_property_read_u32(np, "v3-gain",
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| 				 &pdata->v3_gain) < 0) {
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| 		dev_err(dev, "%pOF has no 'v3-gain' property\n", np);
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| 		return -EINVAL;
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| 	}
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| 
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| 	np = of_get_child_by_name(np, "regulators");
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| 	if (!np) {
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| 		dev_err(dev, "missing 'regulators' subnode in DT\n");
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| 		return -EINVAL;
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| 	}
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| 
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| 	for (i = 0; i < ARRAY_SIZE(rmatch); i++)
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| 		rmatch[i].name = max1586_reg[i].name;
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| 
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| 	matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch));
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| 	of_node_put(np);
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| 	/*
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| 	 * If matched is 0, ie. neither Output_V3 nor Output_V6 have been found,
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| 	 * return 0, which signals the normal situation where no subregulator is
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| 	 * available. This is normal because the max1586 doesn't provide any
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| 	 * readback support, so the subregulators can't report any status
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| 	 * anyway.  If matched < 0, return the error.
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| 	 */
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| 	if (matched <= 0)
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| 		return matched;
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| 
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| 	pdata->subdevs = devm_kcalloc(dev,
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| 				      matched,
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| 				      sizeof(struct max1586_subdev_data),
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| 				      GFP_KERNEL);
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| 	if (!pdata->subdevs)
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| 		return -ENOMEM;
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| 
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| 	pdata->num_subdevs = matched;
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| 	sub = pdata->subdevs;
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| 
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| 	for (i = 0; i < matched; i++) {
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| 		sub->id = i;
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| 		sub->name = rmatch[i].of_node->name;
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| 		sub->platform_data = rmatch[i].init_data;
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| 		sub++;
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| 	}
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| 
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| 	return 0;
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| }
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| 
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| static const struct of_device_id max1586_of_match[] = {
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| 	{ .compatible = "maxim,max1586", },
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| 	{},
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| };
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| MODULE_DEVICE_TABLE(of, max1586_of_match);
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| 
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| static int max1586_pmic_probe(struct i2c_client *client,
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| 					const struct i2c_device_id *i2c_id)
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| {
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| 	struct max1586_platform_data *pdata, pdata_of;
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| 	struct regulator_config config = { };
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| 	struct max1586_data *max1586;
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| 	int i, id, ret;
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| 	const struct of_device_id *match;
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| 
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| 	pdata = dev_get_platdata(&client->dev);
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| 	if (client->dev.of_node && !pdata) {
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| 		match = of_match_device(of_match_ptr(max1586_of_match),
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| 					&client->dev);
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| 		if (!match) {
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| 			dev_err(&client->dev, "Error: No device match found\n");
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| 			return -ENODEV;
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| 		}
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| 		ret = of_get_max1586_platform_data(&client->dev, &pdata_of);
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| 		if (ret < 0)
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| 			return ret;
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| 		pdata = &pdata_of;
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| 	}
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| 
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| 	max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data),
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| 			GFP_KERNEL);
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| 	if (!max1586)
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| 		return -ENOMEM;
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| 
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| 	max1586->client = client;
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| 
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| 	if (!pdata->v3_gain)
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| 		return -EINVAL;
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| 
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| 	max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
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| 	max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
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| 
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| 	/* Set curr_sel to default voltage on power-up */
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| 	max1586->v3_curr_sel = 24; /* 1.3V */
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| 	max1586->v6_curr_sel = 0;
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| 
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| 	for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
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| 		struct regulator_dev *rdev;
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| 
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| 		id = pdata->subdevs[i].id;
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| 		if (!pdata->subdevs[i].platform_data)
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| 			continue;
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| 		if (id < MAX1586_V3 || id > MAX1586_V6) {
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| 			dev_err(&client->dev, "invalid regulator id %d\n", id);
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| 			return -EINVAL;
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| 		}
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| 
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| 		if (id == MAX1586_V3) {
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| 			max1586_reg[id].min_uV = max1586->min_uV;
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| 			max1586_reg[id].uV_step =
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| 					(max1586->max_uV - max1586->min_uV) /
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| 					MAX1586_V3_MAX_VSEL;
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| 		}
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| 
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| 		config.dev = &client->dev;
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| 		config.init_data = pdata->subdevs[i].platform_data;
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| 		config.driver_data = max1586;
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| 
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| 		rdev = devm_regulator_register(&client->dev,
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| 						  &max1586_reg[id], &config);
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| 		if (IS_ERR(rdev)) {
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| 			dev_err(&client->dev, "failed to register %s\n",
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| 				max1586_reg[id].name);
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| 			return PTR_ERR(rdev);
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| 		}
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| 	}
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| 
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| 	i2c_set_clientdata(client, max1586);
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| 	dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
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| 	return 0;
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| }
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| 
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| static const struct i2c_device_id max1586_id[] = {
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| 	{ "max1586", 0 },
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| 	{ }
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| };
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| MODULE_DEVICE_TABLE(i2c, max1586_id);
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| 
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| static struct i2c_driver max1586_pmic_driver = {
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| 	.probe = max1586_pmic_probe,
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| 	.driver		= {
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| 		.name	= "max1586",
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| 		.of_match_table = of_match_ptr(max1586_of_match),
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| 	},
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| 	.id_table	= max1586_id,
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| };
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| 
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| static int __init max1586_pmic_init(void)
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| {
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| 	return i2c_add_driver(&max1586_pmic_driver);
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| }
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| subsys_initcall(max1586_pmic_init);
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| 
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| static void __exit max1586_pmic_exit(void)
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| {
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| 	i2c_del_driver(&max1586_pmic_driver);
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| }
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| module_exit(max1586_pmic_exit);
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| 
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| /* Module information */
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| MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
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| MODULE_AUTHOR("Robert Jarzmik");
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| MODULE_LICENSE("GPL");
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